$ { \left[\begin{array}{rr}{3} & {-1} \\ {1} & {1} \\ {0} & {-2}\end{array}\right]+\left[\begin{array}{rr}{1} & {4} \\ {3} & {1} \\ {0} & {4}\end{array}\right] = {?} } $
To find the sum of two matrices, add the corresponding items between each matrix. ${\left[\begin{array}{rr}{3}+{1} & {-1}+{4} \\ {1}+{3} & {1}+{1} \\ {0}+{0} & {-2}+{4}\end{array}\right]}$ Now, simplify: ${\left[\begin{array}{rr}{4} & {3} \\ {4} & {2} \\ {0} & {2}\end{array}\right]}$